Precise measurement of theX K emission rate following the electron capture-decay of54Mn-fluorescence yield ? K of Cr

Abstract

This determination was made using the electron capture decay of 54Mn. Two methods were employed to measure the K X-ray emission rate: by means of a pressurized 4re proportional counter with the gas at 1.5 MPa, and by means of a medium geometry-defined solid angle counter. The final result was 0~k = 0.2901_+ 0.003. Special care was taken in determining the corrections, some of which do not appear to have been allowed for so far. It is noteworthy that additional corrections, each about + 3 %, had to be applied to the results obtained with each of the two methods. Thus there remains complete agreement between them, but at a higher value of (ok than those appearing in recent publications.

The electron capture decay of85Sr-measurements of theK X-Ray emission probability, half-life, and decay scheme

“…This was to make certain there was no layer of counting gas between the celluloid foils used to stop the Auger electrons. Even a small layer of gas at high pressure can seriously effect the X-ray count rate [3,8]. To obtain the total 4~ emission rate the counts from the two halves of the counter were added.…”

“…At present, calculations of Pr are considered to be more accurate than those of m r , and this fact has been used by several workers to obtain c% from a measurement of Print. Although experimentally measured fluorescence yields for different elements are often quoted with uncertainties of the order of I%, the difference between measured values is frequently several times greater than this, and it has been suggested recently by Magnier et al [3] that some of the corrections involved in the measurements have not always been sufficiently carefully considered. There is thus still a need for accurate measurements of fluorescence yields to test the theoretical calculations.…”